Pope Francis said on Sunday that he was pained by the discovery of the remains of 215 children at a former Catholic school for indigenous students in Canada and called for respect of the rights and culture of native peoples.

He urged Canadian political and Catholic religious leaders to "cooperate with determination" to shed light on the finding and to seek reconciliation and healing. Francis said he felt close to "the Canadian people, who have been traumatized by the shocking news."

Speaking to pilgrims and tourists in St. Peter's Square, he stopped short, however, of the direct apology that many Canadians had demanded from the Catholic Church for its role in the residential schools, which operated between 1831 and 1996 and were run by a number of Christian denominations on behalf of the government.

The discovery last month of the remains of the children at the Kamloops Indian Residential School in British Columbia, which closed in 1978, has reopened old wounds and is fueling outrage in Canada about the lack of information and accountability.

The residential school system forcibly separated about 150,000 children from their homes. Many were subjected to abuse, rape and malnutrition in what the Truth and Reconciliation Commission in 2015 called "cultural genocide."

Francis spoke two days after Canadian Prime Minister Justin Trudeau said the Catholic Church must take responsibility for its role in running many of the schools.